With image display apparatuses displaying three-dimensional images, viewers can view the three-dimensional images with naked eyes without using special glasses. Such an image display apparatus displays a plurality of images from different viewpoints, and controls light beams for the images with a parallax barrier or a lenticular lens, for example. The controlled light beams are guided to the eyes of a viewer. If the viewing position of the viewer is appropriate, the viewer can recognize a three-dimensional image. A region where a viewer can view a three-dimensional image in this manner is referred to as a viewing zone.
There is, however, a disadvantage that the viewing zone is limited. For example, there exists a region where a point of view of an image perceived by the left eye is relatively on the right of a point of view of an image perceived by the right eye. Such a pseudoscopic region that is a viewing position where the three-dimensional image cannot be correctly recognized exists in the real space. Accordingly, the viewing zone is set according to the position of the viewer.
For example, the position of the viewer is detected by a sensor, and the position of the viewing zone is obtained according to the position of the viewer by replacing the image for the right eye and the image for the left eye with each other. A method for correcting a deviation of a panel optical axis of a displaying device in an image display apparatus has also been disclosed. In addition, a method for estimating the posture of a camera that detects the position of the viewer has also been disclosed. The detected position of the viewer can be corrected by using the estimation result.
In the related art, however, when a design error at the displaying device displaying a three-dimensional image and an installation error of a detector detecting the viewer occurred at the same time, the displaying device and the detector need to be adjusted separately.